1. Field
The invention relates to the field of fiber optics for optical communications. More specifically it relates to fiber optic modules that can withstand solder reflow assembly.
2. Background
Fiber optic modules combine semiconductor components, such as application specific integrated circuitry (ASIC), diode lasers and diode photodetectors, into a single package. This package has an electrical interface to a higher level assembly (typically a printed circuit board (PCB)) and an optical interface to fibers. The electrical interface can be a connector to make a ‘pluggable’ module, for example in small form-factor pluggable (SFP). The fiber optical module can be assembled within a cable with an electrical connector, for example in an active optical cable (AOC). This type of packaging protects the fiber optic module from the high temperatures and exposure to post-reflow aqueous wash.
Fiber optic modules provide efficient optical coupling between optoelectronic (OE) devices and fibers. OE devices can be light emitters, such as lasers, and LEDs, and light detectors, such as PIN diodes. This optical coupling can be performed with a component containing lenses and features for aligning the fibers and OE devices to the lenses. This component can be formed by precision molding of plastic. Plastic has a much larger coefficient of thermal expansion than the semiconductor devices.
The process of solder reflow assembly exposes components to a large temperature gradient and a post reflow washing. This high temperature can damage the plastic through deformation or misalign the lenses from the fiber or OE devices. Moisture from the washing process can contaminate the optical path if the path is not sealed.
Therefore, there are several concerns of thermal mismatch as well as contamination of connection from using a fiber optic connector (fiber connector). Accordingly, there has been a long-standing need in the optical community for systems and methods that provide better match/minimize contamination. The following description provides details of various systems and methods that address the above and other concerns in the optical community.